1. Field of the Invention
The present invention relates to a thermal printer in which various types of information are printed on a recording sheet pulled out of roll paper.
2. Description of the Related Art
Thermal printers of various types are provided at present in which printing is performed by pressing a heated thermal head against a special recording sheet which undergoes a color change when heat is applied thereto.
In particular, smooth printing of characters and printing of a variety of graphics are possible without using a toner, an ink or the like, and hence the thermal printer is provided, for example, in a case such as a checkout machine at a parking or that of an oil dispenser at a self-service gas station, a ticket-vending machine provided in various restaurants, and an ATM (Automatic Teller Machine) at a bank to be suitably used for printing of various labels, receipts and tickets.
For example, in the case of the ticket-vending machine among the above-mentioned checkout machine, ticket-vending machine, ATM and the like, a purchased ticket and a receipt for proving the purchase of the ticket are sometimes issued by the same ticket-vending machine. In this case, the thermal printer described above cannot be used in a diversified manner, for example, to discharge the sheets printed with different print patterns from the single thermal printer while sorting the sheets according to the print patterns.
On the other hand, for example, in patent document JP 61-287661 A, in an image forming apparatus such as a copy machine, a laser printer, a liquid crystal printer, an ion printer, and a printing device, there is known a structure including a slide unit for moving a discharge tray in a direction (horizontal direction) different from a discharge direction of the sheets for each group of the discharged sheets to sort the discharged sheets into the groups.
In the above-mentioned structure of Patent Document 1, however, the structure allows the discharged sheets to be sorted by sliding the discharge tray. Therefore, it is necessary to provide a complex mechanism for sliding the discharge tray. As a result, an increase in apparatus size and an increase in manufacturing cost are brought about.
Moreover, when the above-mentioned structure of Patent Document 1 is used for, for example, the ticket-vending machine including the thermal printer provided in the case, it becomes hard for a user to receive the receipt or the ticket with the structure in which the discharge tray slides. Further, the discharge tray is exposed externally from the case and a large indefinite number of users touch the discharge tray in the case of the ticket-vending machine described above or the like, and hence a load is applied on the discharge tray to cause an early breakdown.